PROGRAM SUMMARY

The Mineral Resources and Mineral Hazards Mapping Program (MRMHMP) provides data about California's varied non-fuel mineral resources (such as metals and industrial minerals), naturally occurring mineral hazards (such as asbestos, radon, and mercury), and information about active and historic mining activities throughout the state. Mineral-related reports and maps are published and are routinely disseminated to governmental agencies, universities, and repository libraries. These reports and maps are also available for purchase by mining companies, developers, consultants, and the public at various California Geological Survey (CGS) offices (see Publications). Older reports are available in paper format; some newer reports are available in paper and digital formats compatible with commonly used Geographic Information System (GIS) software. The MRMHMP is divided into two projects; the Mineral Resources Project and the Mineral Hazards Project.

MINERAL RESOURCES PROJECT

The California Geological Survey (CGS) Mineral Resources Project provides objective geologic expertise and information about California’s diverse non-fuel mineral resources. Maps, reports, and other data products developed by the staff assist governmental agencies, mining companies, consultants, and the public in recognizing, developing, and protecting important mineral resources. California ranks first in the U.S. in non-fuel mineral production; in 2001, over 32 non-fuel mineral commodities - valued at $3.27 billion dollars - were produced from 922 California mines. The primary focus of the Mineral Resources Project is to classify lands throughout the state that contain regionally significant mineral resources as mandated by the Surface Mining and Reclamation Act of 1975 (SMARA).

SMARA MINERAL LAND CLASSIFICATION PROJECT

The process of inventorying the non-fuel mineral resources of the state is called mineral land classification, a principal responsibility of the MRMHMP. In 1975, the California legislature enacted the Surface Mining and Reclamation Act (SMARA). This act provides for the reclamation of mined lands and directs the State Geologist to classify (identify and map) the non-fuel mineral resources of the state to show where economically significant mineral deposits occur and where they are likely to occur based upon the best available scientific data. Reclamation of mined lands falls within the purview of the Department of Conservation's Office of Mine Reclamation. Mineral land classification ("classification") is the principal responsibility of the MRMHMP.

The non-fuel mineral resources include the metals such as gold, silver, iron and copper; the industrial minerals such as boron compounds, rare-earth elements, clays, limestone, gypsum, salt and dimension stone; and construction aggregate which includes sand and gravel, and crushed stone. These materials occur in unique geological settings and, therefore, must be mined where they are found. Although land-use competition between mining and other interests is inevitable, it need not be contentious if adequate planning based on objective and accurate mineral resource data are made available to local land-use planners, elected decision makers, the mining industry, and the public.

The Mineral Land Classification Project provides objective classification maps, technical mineral resource data, and mineral-related economic investigations about economically exploitable non-fuel mineral resources in the state. The information presented in classification reports is as accurate as is feasible to assemble at the time of the study. Mineral land planning decisions made today will impact future generations. The intent of classification is to assist lead agencies, planners, and the public in the wise use, management, and conservation of California’s mineral resources.

Since its inception in 1978, the Mineral Land Classification Project has completed 97 classification studies covering about 34% of the state. Thirty two of these studies, covering about 25% of the state, contain resource areas that provide construction aggregate to over 90% of California’s population. Although all mineral commodities mined in California are studied, special emphasis has been given construction aggregate because it is the state’s most important mineral commodity in terms of tonnage, value, and societal infrastructure. As California’s population continues to expand, the demand for minerals - especially building construction minerals such as aggregate - will similarly grow. Over 90% of these essential construction resources are transported by truck because unit trains and marine transport, although used, are currently uncommon in the state. Because such high-volume low-cost construction minerals are expensive to transport, and in order to minimize the environmental affects of trucking these resources from distant sources, it is beneficial - both economically and environmentally - that sand, gravel, and crushed stone resources be mined in reasonable proximity to growing communities.

MINERAL HAZARDS PROJECT

The Mineral Hazards Project provides maps, technical information and advice, and monitors activities about minerals-related environmental and public health issues such as naturally occurring heavy metals, asbestos, mercury and radon. Staff are involved in a CalFed funded project to provide information on natural sources of mercury as well as mercury from historic mercury mining activities in the Cache Creek watershed in the Coast Ranges north of San Francisco. As a follow-up to recommendations of the State Air Resources Board (ARB) Asbestos Task Force, staff prepared a statewide map of potential asbestos host rocks. Staff also completed a pilot project to identify areas more likely to contain naturally occurring asbestos (NOA) in western El Dorado County, that serves as a model for NOA studies in other areas of the state. The Project is entering into an interagency agreement with Caltrans, to provide information on NOA occurrence for use in highway construction and maintenance projects throughout the state. Staff will also develop information on NOA for use in training of Caltrans staff. Staff are working with DHS to develop a statewide map and database on radon occurrence, and have completed studies in Santa Barbara and Ventura counties to identify source rocks and soils associated with radon detected in homes and commercial buildings. Staff also completed studies of radon occurrence in schools in various areas of the state. The Project is also under contract with the U.S. Geological Survey to provide up-dated information on certain precious- and base-metal mines throughout the state for use in mineral resource as well as environmental studies.